Is it possible

[$harp$hooter]

Just wondering if it is possible, without much fettling to swap barrels on a BSA Lightning XL from .177 to .22. I kind of like to thought of a single platform in different calibers without owning the 2 guns individually.

Does anyone know if it is simple swap over over barrels and cocking arms and also if there are any associated risks with putting a .22 barrel on a .177 action?

[Biker_Bob]

Fitting a .22 barrel on a .177 action will result in an over-power gun.
You'll need to de-tune it so that it runs about 10fltb in .177 to give you high 11's in .22
To me the resulting loss in velocity of the .177 defeats the point of having the .177 in the first place.
Not to mention the faff of changing over and the uneven wear on the breech jaws vs the two breech blocks which will affect the lock up and accuracy.
I'd give it a miss (pun intended)

[$harp$hooter]

Fitting a .22 barrel on a .177 action will result in an over-power gun.
You'll need to de-tune it so that it runs about 10fltb in .177 to give you high 11's in .22
To me the resulting loss in velocity of the .177 defeats the point of having the .177 in the first place.
Not to mention the faff of changing over and the uneven wear on the breech jaws vs the two breech blocks which will affect the lock up and accuracy.
I'd give it a miss (pun intended)

I thought as much. I had read a thread on here where someone had put the .177 gas ram into a .22 and it resulted in being FAC rated unwillingly and thought swapping the barrel on a .177 may achieve the same result.

Looking into a second gun in .22 it is!

[Fluffybuck]

Many .177 Lightnings seem to run at 10-11ftlb so some might just about stay below 12ftlb with a .22 barrel.

If the larger calibre barrel were slightly shortened it would allow both barrels to shoot at the same muzzle energy - I proved this with a TXHC which was originally .177cal with standard 9.5" Walther barrel and is now .25cal with custom 6.5" .25cal Walther barrel shooting with the same internals and at the same 11ftlb muzzle energy as it did when it was .177.

In some cases (not the Lightning) changing barrel length or calibre doesn't always have the expected effect; it depends on whether the barrel was longer than necessary to start with.

[$harp$hooter]

Many .177 Lightnings seem to run at 10-11ftlb so some might just about stay below 12ftlb with a .22 barrel.

If the larger calibre barrel were slightly shortened it would allow both barrels to shoot at the same muzzle energy - I proved this with a TXHC which was originally .177cal with standard 9.5" Walther barrel and is now .25cal with custom 6.5" .25cal Walther barrel shooting with the same internals and at the same 11ftlb muzzle energy as it did when it was .177.

In some cases (not the Lightning) changing barrel length or calibre doesn't always have the expected effect; it depends on whether the barrel was longer than necessary to start with.

So it is possible to do but there is a bit of fettling required with the barrel length to make it sub 12ft/lbs. Am I right in thinking the same also applies if you went up to a .25 barrel as does with a .22?

[TDes]

Someone on here (a long time ago) had an HW80 with a quick release system to change barrels.

T

[dannyboy8133]

Is this not a airgunning myth? Remembering vaguely that force = mass x velocity (or similiar) surely the equivlent air pressure that propels a .177 at a given velocity to produce 12 ftlb would propel a heavier projectile at 12 ftlb = a lower velocity. If someone cleverer could explain Id be grateful and how are Beeman getting around this with their dual calibre effort? Cos you canne break the laws of physics (unless it suits the script!)?

[simesgee]

Is this not a airgunning myth? Remembering vaguely that force = mass x velocity (or similiar) surely the equivlent air pressure that propels a .177 at a given velocity to produce 12 ftlb would propel a heavier projectile at 12 ftlb = a lower velocity. If someone cleverer could explain Id be grateful and how are Beeman getting around this with their dual calibre effort? Cos you canne break the laws of physics (unless it suits the script!)?

It is more efficient to accelerate a large mass by a bit, than to accelerate a small mass by a lot. That is why passenger aircraft engines have this big fan on the front - to suck in a great mass of air and accelerate it a relatively small amount.

As a .22 is greater in mass but leaves with a lower velocity than a .177 the air is used more efficiently.
Hope that helps!
Simes.

[dannyboy8133]

It is more efficient to accelerate a large mass by a bit, than to accelerate a small mass by a lot. That is why passenger aircraft engines have this big fan on the front - to suck in a great mass of air and accelerate it a relatively small amount.

As a .22 is greater in mass but leaves with a lower velocity than a .177 the air is used more efficiently.
Hope that helps!
Simes.

Clever clogs - - so the Beeman in .177 must be way down then. What a pointless rifle then.

[Fluffybuck]

Is this not a airgunning myth? Remembering vaguely that force = mass x velocity (or similiar) surely the equivlent air pressure that propels a .177 at a given velocity to produce 12 ftlb would propel a heavier projectile at 12 ftlb = a lower velocity. If someone cleverer could explain Id be grateful and how are Beeman getting around this with their dual calibre effort? Cos you canne break the laws of physics (unless it suits the script!)?

If the barrel is long enough, both .177 and .22 will give similar muzzle energy.
If you swap the barrels between a .177 and .22 Theoben Evolution (not the carbine version) the two guns will still shoot at roughly the same 11+ftlb energy. The 10.5" .177 and .22 barrels - and the 7.5" .22 - are fully efficient due to the quirks of the powerplant.

In 12ftlb spring guns that length where .177 and .22 shoot at similar muzzle energy with the same powerplant is somewhere between 12-18 inches depending on the gun. In older airguns which didn't get close to 12ftlb such as those used in Mr.Cardew's experiments the barrel only needs to be several inches long.
With a PCP and especially at FAC power it's about twice the length of a springer, hence the FAC HW100 has a barrel twice as long (24") as the 12ftlb carbine version (12") and 1.5x as long as the 12ftlb standard version (16").

However, not everyone wants a long barrel because they can get in the way when hunting or can make the gun front-heavy.

So the other alternative for a gun with two different calibre barrels is to have them in different lengths as in the example of my TXHC which went from 9.5" .177cal to 6.5" .25cal and runs at roughly the same muzzle energy with the original internals.

[dannyboy8133]

Cheers - every day IS a school day.